#!/usr/bin/env python3
"""
Capture le bruit de fond du détecteur sur 24h (sans source).
Gère le débranchement/rebranchement du détecteur.
À lancer séparément avant le moniteur :
    docker-compose run --rm detect python capture_background.py
"""
import numpy as np
import time
import json
import os

SAMPLE_INTERVAL = int(os.environ.get("SAMPLE_INTERVAL", "60"))
RESET_INTERVAL = int(os.environ.get("RESET_INTERVAL", "3600"))  # Reset detector every N seconds (default: 1h)
TARGET_DURATION = int(os.environ.get("TARGET_DURATION", str(86400)))  # 24h
OUTPUT_PATH = os.environ.get("BACKGROUND_PATH", "/data/background_24h.npy")
SNAPSHOT_PATH = os.environ.get("SNAPSHOT_PATH", "/data/background_snapshot.json")

BG_COUNTS = np.zeros(1024, dtype=np.float64)
BG_LIVE_TIME = 0.0
device = None
last_counts = None
last_live_time = None
last_reset_time = 0

# Resume from previous snapshot if it exists
if os.path.exists(SNAPSHOT_PATH):
    try:
        with open(SNAPSHOT_PATH) as _f:
            _prev = json.load(_f)
        _prev_spectrum = _prev.get("spectrum", [])
        if len(_prev_spectrum) == 1024:
            BG_COUNTS = np.array(_prev_spectrum, dtype=np.float64)
            BG_LIVE_TIME = float(_prev.get("live_time_s", 0))
            print(f"Snapshot anterieur charge : {BG_LIVE_TIME:.0f}s live, {BG_COUNTS.sum():.0f} coups")
    except Exception as _e:
        print(f"Impossible de charger le snapshot anterieur : {_e}")

def save_snapshot():
    """Save a human-readable snapshot of current background."""
    cps = BG_COUNTS.sum() / BG_LIVE_TIME if BG_LIVE_TIME > 0 else 0
    # Approximate energy calibration for RC-103: E ≈ 0.33 + 2.97*ch
    peaks = []
    max_c = BG_COUNTS.max()
    if max_c > 0:
        for i, c in enumerate(BG_COUNTS):
            if c > max_c * 0.03:
                energy = 0.33 + 2.97 * i
                peaks.append({"channel": i, "energy_kev": round(energy, 1), "counts": round(float(c), 1)})

    snapshot = {
        "elapsed_hours": round((time.time() - start) / 3600, 2),
        "live_time_s": round(BG_LIVE_TIME, 1),
        "total_counts": round(float(BG_COUNTS.sum()), 0),
        "cps": round(cps, 2),
        "top_peaks": sorted(peaks, key=lambda x: -x["counts"])[:15],
        "spectrum": [round(float(c), 1) for c in BG_COUNTS],
    }
    with open(SNAPSHOT_PATH, "w") as f:
        json.dump(snapshot, f, indent=2)

print(f"Capture du bruit de fond pendant {TARGET_DURATION/3600:.0f}h...")
print("Assurez-vous qu'aucune source radioactive n'est a proximite du detecteur.")
print()

start_offset = 0
if os.path.exists(SNAPSHOT_PATH):
    try:
        with open(SNAPSHOT_PATH) as _f:
            _prev = json.load(_f)
        start_offset = float(_prev.get("elapsed_hours", 0)) * 3600
    except Exception:
        pass

start = time.time() - start_offset
last_reset_time = time.time()

while (time.time() - start) < TARGET_DURATION:
    time.sleep(SAMPLE_INTERVAL)
    try:
        if device is None:
            from radiacode import RadiaCode

            device = RadiaCode()
            device.spectrum_reset()
            last_counts = None
            last_live_time = None
            last_reset_time = time.time()
            print("Radiacode connecte.")

        spectrum = device.spectrum()
        counts = np.array(spectrum.counts, dtype=np.float64)
        live_time = spectrum.duration.total_seconds()

        # Compute delta since last read (avoid double-counting)
        if last_counts is not None and last_live_time is not None:
            delta_counts = counts - last_counts
            delta_live_time = live_time - last_live_time
            # If detector was reset externally, delta would be negative
            if delta_counts.sum() < 0 or delta_live_time < 0:
                delta_counts = counts
                delta_live_time = live_time
            BG_COUNTS += delta_counts
            BG_LIVE_TIME += max(delta_live_time, 0)
        else:
            BG_COUNTS += counts
            BG_LIVE_TIME += live_time

        last_counts = counts.copy()
        last_live_time = live_time

        # Only reset detector spectrum at RESET_INTERVAL
        now = time.time()
        if now - last_reset_time >= RESET_INTERVAL:
            device.spectrum_reset()
            last_counts = None
            last_live_time = None
            last_reset_time = now
            print(f"  → Reset détecteur (intervalle {RESET_INTERVAL}s)")

        elapsed = time.time() - start
        cps = BG_COUNTS.sum() / BG_LIVE_TIME if BG_LIVE_TIME > 0 else 0
        print(
            f"Background : {elapsed/3600:.1f}h / {TARGET_DURATION/3600:.1f}h "
            f"({BG_LIVE_TIME:.0f}s live, {BG_COUNTS.sum():.0f} coups, {cps:.1f} CPS)",
            flush=True,
        )
        save_snapshot()
    except Exception as e:
        print(f"\nErreur : {e}, reconnexion...")
        device = None
        last_counts = None
        last_live_time = None

os.makedirs(os.path.dirname(OUTPUT_PATH) if os.path.dirname(OUTPUT_PATH) else ".", exist_ok=True)
np.save(
    OUTPUT_PATH,
    {
        "counts": BG_COUNTS,
        "duration": BG_LIVE_TIME,
        "timestamp": time.time(),
    },
)
print(f"\n\nBackground sauvegarde : {OUTPUT_PATH}")
print(f"  Duree live : {BG_LIVE_TIME/3600:.1f}h")
print(f"  Total coups : {BG_COUNTS.sum():.0f}")
print(f"  CPS moyen : {BG_COUNTS.sum()/BG_LIVE_TIME:.1f}")